南有桥木不可休思
[nán yŏu qiáo mù bù kĕ xiū sī]
'南有桥木不可休思' translates as There Is A Bridge in the South Under Which Wood Floats But No Respite For Thoughts. It has no direct reference in ancient literature, but it could imply unceasing thoughts like drifting wood in rivers, expressing boundless wandering or unrest mind.